You should not be worried so much and not be so shy.
This lump on the labia majora
can be a:lipoma(fat cell),fibroma(bening solid tumor
)or hydradenoma(originates from the sweat glands) and endometriosis
that is rare.You should not touch because you can irritate the skin around this lump.you should have personal hygiene and you can lubricate with some solution that contains smalls amounts of alcohol.If this lamp continue to stay in same amount and do not rise you should go immediately to the doctor to see what is it.
I hope i help you with my answer